CVE-2015-4166 in Key Trustee Server
Summary
by MITRE
Cloudera Key Trustee Server before 5.4.3 does not store keys synchronously, which might allow attackers to have unspecified impact via vectors related to loss of an encryption key.
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Analysis
by VulDB Data Team • 09/11/2020
The Cloudera Key Trustee Server vulnerability identified as CVE-2015-4166 represents a critical weakness in the cryptographic key management infrastructure of enterprise data platforms. This vulnerability specifically affects versions prior to 5.4.3 and stems from the server's failure to implement synchronous key storage mechanisms. The fundamental issue lies in the asynchronous nature of key persistence operations within the system, creating potential race conditions and data loss scenarios that could compromise the entire encryption framework. Organizations relying on Cloudera's key management services for protecting sensitive data across their Hadoop environments face significant risk when operating with vulnerable versions of the Key Trustee Server component.
The technical flaw manifests as an insufficient synchronization mechanism during key storage operations, where encryption keys are not immediately and reliably persisted to storage before the system acknowledges the operation as complete. This asynchronous behavior creates a window of vulnerability where keys may be lost due to system failures, power outages, or process interruptions occurring between the key generation and storage phases. The weakness directly maps to CWE-116, which addresses improper encoding or handling of synchronous operations, and represents a classic example of inadequate data persistence controls in cryptographic systems. Attackers exploiting this vulnerability could potentially cause key loss that would render encrypted data inaccessible, effectively creating a denial-of-service condition for the entire encrypted data ecosystem while simultaneously compromising the confidentiality guarantees that encryption is designed to provide.
The operational impact of this vulnerability extends beyond simple data unavailability to encompass broader security implications for enterprise environments. When encryption keys are lost due to asynchronous storage failures, organizations face the catastrophic scenario of having no means to decrypt their protected data, leading to complete data loss and potential regulatory compliance violations. The unspecified impact mentioned in the vulnerability description suggests that attackers might leverage this weakness to achieve various malicious objectives including data exfiltration through key compromise, system disruption through encryption key loss, or even privilege escalation by manipulating the key management process. This vulnerability particularly affects organizations using Cloudera Enterprise Edition where data encryption is a core security feature, potentially exposing sensitive business information, customer data, and proprietary intellectual property to unauthorized access.
Organizations should implement immediate mitigation strategies including upgrading to Cloudera Key Trustee Server version 5.4.3 or later, which addresses the synchronous storage implementation. System administrators must also establish robust monitoring procedures to detect key storage failures and implement redundant storage mechanisms to prevent single points of failure. The remediation process should include comprehensive testing of key recovery procedures to ensure that encryption key persistence mechanisms function correctly under various failure scenarios. Additionally, organizations should consider implementing backup and recovery procedures for key management systems, following the principles outlined in NIST SP 800-57 for cryptographic key management. The vulnerability highlights the critical importance of synchronous operations in cryptographic systems and serves as a reminder of the fundamental security requirements for key management infrastructure that aligns with ATT&CK technique T1552.001 for credentials from password storage and T1486 for data encryption for impact, where the loss of encryption keys can result in complete data compromise and system availability issues.